On Fri, Sep 20, 2019 at 12:36 PM Krish Sadhukhan
<krish.sadhukhan@xxxxxxxxxx> wrote:
>
>
> On 9/19/19 4:02 PM, Jim Mattson wrote:
> > Ensure that support for RDPRU is not enumerated in the guest's CPUID
> > and that the RDPRU instruction raises #UD.
>
>
> The AMD spec says,
>
> "When the CPL>0 with CR4.TSD=1, the RDPRUinstruction will
> generate a #UD fault."
>
> So we don't need to check the CR4.TSD value here ?
KVM should set CPUID Fn8000_0008_EBX[RDPRU] to 0.
However, I should modify the test so it passes (or skips) on hardware. :-)
>
> >
> > Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> > Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
> > ---
> > lib/x86/processor.h | 1 +
> > x86/Makefile.x86_64 | 1 +
> > x86/rdpru.c | 23 +++++++++++++++++++++++
> > x86/unittests.cfg | 5 +++++
> > 4 files changed, 30 insertions(+)
> > create mode 100644 x86/rdpru.c
> >
> > diff --git a/lib/x86/processor.h b/lib/x86/processor.h
> > index b1c579b..121f19c 100644
> > --- a/lib/x86/processor.h
> > +++ b/lib/x86/processor.h
> > @@ -150,6 +150,7 @@ static inline u8 cpuid_maxphyaddr(void)
> > #define X86_FEATURE_RDPID (CPUID(0x7, 0, ECX, 22))
> > #define X86_FEATURE_SPEC_CTRL (CPUID(0x7, 0, EDX, 26))
> > #define X86_FEATURE_NX (CPUID(0x80000001, 0, EDX, 20))
> > +#define X86_FEATURE_RDPRU (CPUID(0x80000008, 0, EBX, 4))
> >
> > /*
> > * AMD CPUID features
> > diff --git a/x86/Makefile.x86_64 b/x86/Makefile.x86_64
> > index 51f9b80..010102b 100644
> > --- a/x86/Makefile.x86_64
> > +++ b/x86/Makefile.x86_64
> > @@ -19,6 +19,7 @@ tests += $(TEST_DIR)/vmx.flat
> > tests += $(TEST_DIR)/tscdeadline_latency.flat
> > tests += $(TEST_DIR)/intel-iommu.flat
> > tests += $(TEST_DIR)/vmware_backdoors.flat
> > +tests += $(TEST_DIR)/rdpru.flat
> >
> > include $(SRCDIR)/$(TEST_DIR)/Makefile.common
> >
> > diff --git a/x86/rdpru.c b/x86/rdpru.c
> > new file mode 100644
> > index 0000000..a298960
> > --- /dev/null
> > +++ b/x86/rdpru.c
> > @@ -0,0 +1,23 @@
> > +/* RDPRU test */
> > +
> > +#include "libcflat.h"
> > +#include "processor.h"
> > +#include "desc.h"
> > +
> > +static int rdpru_checking(void)
> > +{
> > + asm volatile (ASM_TRY("1f")
> > + ".byte 0x0f,0x01,0xfd \n\t" /* rdpru */
> > + "1:" : : "c" (0) : "eax", "edx");
> > + return exception_vector();
> > +}
> > +
> > +int main(int ac, char **av)
> > +{
> > + setup_idt();
> > +
> > + report("RDPRU not supported", !this_cpu_has(X86_FEATURE_RDPRU));
> > + report("RDPRU raises #UD", rdpru_checking() == UD_VECTOR);
> > +
> > + return report_summary();
> > +}
> > diff --git a/x86/unittests.cfg b/x86/unittests.cfg
> > index 694ee3d..9764e18 100644
> > --- a/x86/unittests.cfg
> > +++ b/x86/unittests.cfg
> > @@ -221,6 +221,11 @@ file = pcid.flat
> > extra_params = -cpu qemu64,+pcid
> > arch = x86_64
> >
> > +[rdpru]
> > +file = rdpru.flat
> > +extra_params = -cpu host
> > +arch = x86_64
> > +
> > [umip]
> > file = umip.flat
> > extra_params = -cpu qemu64,+umip
